I. Field
The following description relates generally to wireless communications and more particularly to channel scanning that mitigates network acquisition time and increases system selection performance.
II. Background
Wireless communication systems are widely deployed to provide various types of communication and to communicate information regardless of where a user is located (e.g., inside or outside a structure) and whether a user is stationary or moving (e.g., in a vehicle, walking). For example, voice, data, video and so forth can be provided through wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources. A system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Wireless network market deployments generally include multiple carriers (or networks) and roaming agreements between carriers, referred to as roaming partners. Each carrier usually desires that the mobile device, which has subscribed to that carrier's service (referred to as a home network) perform functions or calls (e.g., data transfer, communication, and so forth) on the home network as long as possible. Only when the mobile device is moving out of the coverage of the home network, or for some other reason cannot obtain home network coverage, should the mobile device transfer to a roaming partner's coverage.
There are at least two motivations for utilizing the home network as long as possible. First, the roaming network might charge the user an additional fee for usage of the roaming partner's coverage, which is referred to as revenue consciousness. Second, the home network can lose revenue because the home network is not being utilized for the particular function or call. Although there are motivations for desiring to mitigate utilization of a roaming service, in some areas (e.g., different geographical areas, such as different states or countries) only the roaming service might be available. For example, on the West Coast of the United States, a first carrier or operator is available and on the East Coast of the United States, the first carrier is not available, but a second carrier is available. Thus, if a user travels from the West Coast to the East Coast, the user would not have service from the first carrier. Further, if roaming service were not available, the user would have no service on the East Coast (e.g., cannot gain access to the second carrier).
In order to utilize a home network as long as possible, conventional services utilize a list of preferred systems (e.g., home system and/or roaming system), which is based on static information. The list would advise a device to scan in a fixed (static) order from a first listed channel and continue through the list until the last channel is scanned and then repeat with the first listed channel (if network acquisition has not occurred). Thus, the static list does not take into account roaming networks or other parameters, but remains static, which can result in a device continuously scanning unavailable channels.